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Text 7. Mouth and Teeth

    1. Your smile is often the first thing people notice when they look at you. Your facial expression attracts other people’s attention. With the help of the teeth your mouth shows a lot of emotions on your face from happiness to anger.

    2. The mouth also plays a key role in the digestive system, but it does much more than get digestion started. The mouth — especially the teeth, lips, and tongue — is essential for speech. The tongue, which allows us to taste, also helps us to form words when we speak. The lips both help to hold food in the mouth while we chew and pronounce words when we talk.

    3. With the lips and tongue, teeth help to form words by controlling air flow out of the mouth. The tongue strikes the teeth as certain sounds are made.

    4. The hardest substances in the body, the teeth are also necessary for chewing (or mastication) — the process by which we tear, cut, and grind food in preparation for swallowing. Each type of tooth serves a different function in the chewing process. Incisors cut foods when you bite into them. The sharper and longer canines tear food. The premolars, which are flatter than the canines, grind and mash food. Molars, with their points and grooves, are responsible for the most vigorous chewing. All the while, the tongue helps to push the food up against our teeth.

    5. During chewing salivary glands in the walls and floor of the mouth secrete saliva, which moistens the food and helps break it down even more. Saliva makes it easier to chew and swallow foods (especially dry foods), and it contains enzymes and lubricants that aid in the digestion of carbohydrates.

    6. Once food has been converted into a soft, moist mass, it's pushed into the throat (or pharynx) at the back of the mouth and is swallowed. When we swallow, the soft palate closes off the nasal passages from the throat to prevent food from entering the nose.

Write down the letter of the paragraph which

tells about the chemicals which help to digest food

1 _____

describes different expressions which your face shows

2 _____

describes particular sounds produced by the tongue and the teeth

3 _____

tells about both speech and digestion in which the mouth and its inner parts play a role

4 _____

tells about further food’s way from the mouth

5 _____

describes each tooth’s function in chewing

6_____

Decide whether the statements are true or false and put (T) or (F) next to the statement

Teeth on their own are able to form words by controlling air flow out of the mouth.

7 _____

Molars do the most energetic work in chewing

8 _____

Saliva assists digestion of carbohydrates

9 _____

The tongue prevents food from entering the nose

10 _____

H. Read Text 8 and complete the tasks below